Earthquake Probability of the “Seismic Gap” on the Longmenshan Fault     

Song Jin  Jiang Haikun  Meng Lingyuan  Zang Yang 《中国地震研究》2018,32(1):15-27

Using the layered viscoelastic medium model, this paper calculated the coulomb stress loading effect on the Lushan epicenter generated by the Wenchuan earthquake. Then combined with the rate-state friction law proposed by Dieterich J. (1994), we obtain the probability of an M_W ≥ 6.0 earthquake occurring in the vicinity of Lushan. The results show that the probability of M_W ≥ 6.0 earthquake of the Lushan region in 2013 is up to 18%, indicating that the stress disturbance caused by the Wenchuan earthquake accelerated the Lushan earthquake. This paper also calculates the coulomb stress accumulation on the "seismic gap" generated by the two earthquakes of Wenchuan and Lushan, and combined with the background seismicity, gives the M_W>6.0 earthquake probability of the "seismic gap". Although there may be a certain error in the results because of the Dayi earthquake, selection of the medium model parameters and background seismicity, the seismic probability of the "seismic gap" is increasing. Thus, we think destructive earthquakes are still likely to occur in the "seismic gap".  相似文献   

New Tools for Assessing Reactive Mineral-Mediated Abiotic Contaminant Transformation     

John Horst  Craig Divine  Jennifer Tilton  Shandra Justicia-León  Shannon Ulrich  Robert J. Stuetzle 《Ground Water Monitoring & Remediation》2019,39(2):12-21

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Diverse protolith ages for the Mindoro and Romblon Metamorphics (Philippines): Evidence from single zircon U–Pb dating          下载免费PDF全文

Ulrich Knittel  Monika Walia  Shigeyuki Suzuki  Carla B. Dimalanta  Graciano P. Yumul Jr. 《Island Arc》2017,26(1)

Within the north‐eastern part of the Palawan Continental Terrane, which forms the south‐western part of the Philippine archipelago, several metamorphic complexes are exposed that are considered to be rifted parts of the Asian margin in South‐East China. The protolith age(s) and correlations of these complexes are contentious. The largest metamorphic complex of the Palawan Continental Terrane comprises the Mindoro Metamorphics. The north‐eastern part of this metamorphic complex has recently been found to be composed of protoliths of Late Carboniferous to Late Permian protolith age. However, meta‐sediments exposed at the westernmost tip and close to the southern boundary of the exposure of the Mindoro Metamorphics contain detrital zircons and with U–Pb ages, determined by LA–ICP–MS, in the range 22–56 Ma. In addition, zircons as young as 112 Ma were found in a sample of the Romblon Metamorphics in Tablas. As the youngest detrital zircons provide an upper age limit for the time of deposition in meta‐sediments, these results suggest that the Mindoro and Romblon Metamorphics comprise protoliths of variable age: Late Carboniferous to Late Permian in NE Mindoro; Eocene or later in NW Mindoro; Miocene at the southern margin of the Mindoro metamorphics; and Cretaceous or later on Tablas. The presence of non‐metamorphic sediments of Late Eocene to Early Oligocene age in Mindoro (Lasala Formation), which are older than the youngest metasediments, suggests that metamorphism of the young meta‐sediments of Mindoro is the result of the collision of the Palawan Continental terrane with the Philippine Mobile Belt in Late Miocene. Similarities of the age spectra of zircons from the Eocene to Miocene metamorphics with the Eocene to Early Miocene Lasala Formation suggest that the protoliths of the young metamorphics may be equivalents of the Lasala Formation or were recycled from the Lasala Formation.  相似文献   

Distribution of glycerol dialkyl glycerol tetraethers in surface soils along an altitudinal transect at cold and humid Mountain Changbai: Implications for the reconstruction of paleoaltimetry and paleoclimate     

Yue Li  Shijin Zhao  Hongye Pei  Shi Qian  Jingjie Zang  Xinyue Dang  Huan Yang 《中国科学:地球科学(英文版)》2018,61(7):925-939

Glycerol Dialkyl Glycerol Tetraethers(GDGTs)serve as important tools for the quantitative reconstruction of paleoclimate and paleoecology in both continental and marine environments.Previous studies of GDGTs in the terrestrial environments focused primarily on the soils from the relatively warm-humid or cold-dry regions.However,it is still unclear how GDGTs respond to environmental variables in the cold-humid regions.Here,we collected soils along an altitudinal transect of Mountain(Mt.)Changbai,which has a typical cold-humid climate,to investigate the distribution of GDGTs and the response of GDGT-based proxies to changes in climate along the transect.The shift in the distribution of archaeal isoprenoidal GDGTs(iso GDGTs)revealed that the archaeal community varied significantly along the transect,which can affect the relationship between TEX_(86)and mean annual air temperature(MAT).In addition,the increased temperature seasonality at higher altitudes exerted a significant impact on TEX_(86).We proposed a global calibration of TEX_(86)for the growing season temperature reconstruction in the soil environments:T=85.19×TEX_(86)-46.30(R~2=0.84,p0.001).The methylation indices for 5-methyl branched GDGTs(br GDGTs)including MBT′_(5me)and MBT_(5/6),showed correlation with soil water content but no relationship with MAT,indicating that MBT′_(5me)and MBT_(5/6)from cold-humid environments may be not suitable for temperature and altitude reconstruction.In contrast,the recently developed p H proxies,including MBT′_(6me)(the methylation index for 6-methyl br GDGTs),CBT(Cyclisation index of Branched Tetraethers),IR_(IIa’)(Isomer ratio of IIa′)and IR_(IIIa′)(Isomer ratio of IIIa′)exhibited significant correlations with soil p H,suggesting these proxies can still be used for soil p H reconstruction in the coldhumid regions.The combination of MBT′_(5me)and MBT′_(6me)was strongly related to different types of climate(cold-dry,warmhumid,cold-humid,and warm-dry).For example,MBT′_(5me)0.65 and MBT′_(6me)0.55 are diagnostic for the cold-humid climate.Thus,the combination of MBT′_(5me)and MBT′_(6me)has the potential as a tool for the identification of different types of paleoclimate.  相似文献   

2023年震情述评     

韩颜颜  臧阳  马亚伟  解孟雨  王月  杨文  张小涛  宋金  姜祥华  史海霞  李飞  孟令媛 《中国地震》2024,40(1):271-278

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Roger J. Tayler: The hidden universe ellis horwood 1991, 213 S. Preis: $ 27.15 ISBN 0-13-388711-1, 0-13-388133-4 pbk     

Ulrich Bleyer 《Astronomische Nachrichten》1993,314(4):302-302

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常州市气象预报业务工作平台   总被引：4，自引：1，他引：3  

董喜春  臧晓钟  束建  周霖华 《气象科技》2008,36(2):253-256

应用网页制作、办公自动化和图像处理软件,利用VB 6.O语言编程研制开发了常州气象预报业务工作平台.常州气象预报业务工作平台入库了1952～2003年常州气候整编资料,建立以资深预报员预报经验指标的天气系统模型,规范以"9210工程"和省市县网络互通互联为依托的预报业务工作流程.应用过程表明,该平台全面实现了人机交互作业方式进行检索、分析、制作和分发各种气象信息,有效地提高了工作效率和预报服务质量.  相似文献   

Stable isotope constraints on the origin of the Cabo de Creus garnet-tourmaline pegmatites,Massif des Alberes,Eastern Pyrenees,Spain     

Klaus-Werner Damm  Russell S. Harmon  Peter-Michael Heppner  Ulrich Dornsiepen 《Geological Journal》1992,27(1):75-86

Pegmatite dyke swarms are exposed within the easternmost Pyrenees at Cabo de Creus. These dykes were emplaced into high-grade metamorphosed sedimentary strata of Cambro-Ordovician age, but lack obvious field relationship to Hercynian intrusive rocks. Together with structural and geochemical data, equilibrium oxygen isotope fractionations at temperatures of ≈ 600°C, the lack of obvious subsolidus exchange, and the H- and O-isotopic signatures of water in equilibrium with pegmatite mica and quartz are interpreted to indicate a derivation from anatexis of a metapelitic source at shallow crustal levels.  相似文献